1. Field of the Invention:
It is well known that conduits for water, sewage, and other liquids frequently require repair because of leakage. The leakage may be due to improper formation or installation of the conduit, deterioration due to aging, subjection to acids or corrosive materials, cracking due to earthquakes or vibrations caused by vehicular travel in the vicinity, improper care, or other causes. Whether the leakage is inwardly from an environment into the conduit or outwardly from the conduit into the environment, it is objectionable because of resulting health hazards, waste, damage to the environment and other difficulties. Unfortunately, corrective measures have generally been very expensive, time consuming, and in many instances virtually ineffective.
2. Description of the Prior Art:
Frequently, such conduits are buried deeply in the ground, sometimes tunnel under mountains or other obstructions, and their uncovering for replacement or repair exceedingly expensive. Modernly, it has become possible to line such conduits while they remain in place and without the expenses and hazards of digging them out. For example, U.S. Pat. Nos. 4,009,063, issued Feb. 22, 1977 and 4,064,211, issued Dec. 20, 1977 on a Pipe Lining and a Lining of Passageways, respectively, disclose highly effective procedures for lining conduits in situ.
However, many conduits requiring repair have laterals extended therefrom. This is particularly true in sewage systems where relatively small laterals carry sewage to larger trunk conduits which ultimately lead to sewage processing plants. When a conduit is lined, the lining covers over and shuts off the laterals. Prior to the present invention, it was necessary to gain access to the junctures of the laterals with their trunk conduits and to cut holes through the liners to admit sewage from the laterals into their trunk conduits. This in many instances was a very expensive procedure entailing the digging out of each such juncture, no matter how deeply buried, and no matter of how frequent occurrence as, for example, in a residential area where laterals frequently are within fifteen meters or so of each other.
As will subsequently become apparent, the present invention makes possible the speedy, economical, and effective porting of conduit linings and the like so as to establish fluid communication between a conduit and laterals extended therefrom. Of course, a liner is simply a form of conduit and the present invention is applicable to the lateral porting of other such forms as well.